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This is a little more than a new game it potentially uncovers a new class of numbers -- though determining membership might become a hard problem.

A number that possesses the solitaire property can be written in as ...,0,...1,...2,...etc, or ...,0,...1,...10...11,...etc,(where the "0" is the first zero in the number), with a radix point anywhere. We are free to pick the base and say it is solitaire with respect to that base. After the initial 0, the subsequent ordinals (the 1,2, etc or the 1,10,11, etc) used to write the solitaire number don't have to be the first ones. For example:

pi=3.1415926535897932384626433832795
0 2884
1 971693993751058
2 0974944592
3 078163860
4 ...
etc.,

or

pi=3.1415926535897932384626433832795

0 2884197

1 6939937510582 097494459

2 3 07816

3 860
4 ...
etc.,are both acceptable. (If the number can be written as  ...,0,...1,...2,...etc, or ...,0,...1,...10...11,...etc. it is solitaire.)

The Champernowne constant with respect to base 10 has only one representation:

0.

1

2

3

4

5

6

7

8

9

10

11...

etc. .

 

I know Base 10 Champernowne constant is base 10 solitaire. I can not say the same with certainty for Pi.

I also propose we can measure the solitude of a number by the average amount of numbers between the 0,1,2,3..., and give a perfect solitude score to Base 10 Champernowne constant. Other constants can be given additional credit, of some kind, if the amounts of numbers between the 1,2,3... follow a specific preset pattern.

 

 

marvinrayburns.com

 

With the package VectorCalculus we can study the speed and acceleration to their respective components. Considering the visualizaccion and algebraic calculations and to check with their respective commands. Both 2D and 3D.

 

Velocidad-Aceleració.mw     (in spanish)

 

Lenin Araujo Castillo

Physics Pure

Computer Science

The attached presentation is the last one of a sequence of three on Quantum Mechanics using Computer Algebra, covering the field equation for a quantum system of identical particles, its stationary solutions and the equations for small perturbations around them and, in this third presentation, the conditions for superfluidity of such a system of identical particles at low temperature. The novelty is again in how to tackle these problems in a computer algebra worksheet.

The Landau criterion for Superfluidity
  

Pascal Szriftgiser1 and Edgardo S. Cheb-Terrab2 

(1) Laboratoire PhLAM, UMR CNRS 8523, Université Lille 1, F-59655, France

(2) Maplesoft, Canada

 

A Bose-Einstein Condensate (BEC) is a medium constituted by identical bosonic particles at very low temperature that all share the same quantum wave function. Let's consider an impurity of mass M, moving inside a BEC, its interaction with the condensate being weak. At some point the impurity might create an excitation of energy `&hbar;`*omega[k] and momentum `&hbar;` `#mover(mi("k"),mo("&rarr;"))`. We assume that this excitation is well described by Bogoliubov's equations for small perturbations `&delta;&varphi;` around the stationary solutions `&varphi;```of the field equations for the system. In that case, the Landau criterion for superfluidity states that if the impurity velocityLinearAlgebra[Norm](`#mover(mi("v"),mo("&rarr;"))`) is lower than a critical velocity v[c] (equal to the BEC sound velocity), no excitation can be created (or destroyed) by the impurity. Otherwise, it would violate conservation of energy and momentum. So that, if LinearAlgebra[Norm](`#mover(mi("v"),mo("&rarr;"))`) < v[c] the impurity will move within the condensate without dissipation or momentum exchange, the condensate is superfluid (Phys. Rev. Lett. 85, 483 (2000)). Note: low temperature liquid 4He is a well known example of superfluid that can, for instance, flow through narrow capillaries with no dissipation. However, for superfluid helium, the critical velocity is lower than the sound velocity. This is explained by the fact that liquid 4He is a strongly interacting medium. We are here rather considering the case of weakly interacting cold atomic gases.

Landau criterion for superfluidity

 

 

Background: For a BEC close to its ground state (at temperature T = 0 K), its excitations are well described by small perturbations around the stationary state of the BEC. The energy of an excitation is then given by the Bogoliubov dispersion relation (derived previously in Mapleprimes "Quantum Mechanics using computer algebra II").

 

epsilon[k] = `&hbar;`*omega[k] and `&hbar;`*omega[k] = `&+-`(sqrt(k^4*`&hbar;`^4/(4*m^2)+k^2*`&hbar;`^2*G*n/m))

 

where G is the atom-atom interaction constant, n is the density of particles, m is the mass of the condensed particles, k is the wave-vector of the excitations and omega[k] their pulsation (2*Pi time the frequency). Typically, there are two possible types of excitations, depending on the wave-vector k:

• 

In the limit: proc (k) options operator, arrow; 0 end proc, "epsilon[k]&sim;`&hbar;`*k*"v[c] with v[c] = sqrt(G*n/m), this relation is linear in k and is typical of a massless quasi-particle, i.e. a phonon excitation.

• 

In the limit: proc (k) options operator, arrow; infinity end proc, `&sim;`(epsilon[k], `&hbar;`^2*k^2/(2*m)) which is the dispersion relation of a free particle of mass "m,"i.e. one single atom of the BEC.

 

Problem: An impurity of mass M moves with velocity `#mover(mi("v"),mo("&rarr;"))` within such a condensate and creates an excitation with wave-vector `#mover(mi("k"),mo("&rarr;"))`. After the interaction process, the impurity is scattered with velocity `#mover(mi("w"),mo("&rarr;"))`.

 

a) Departing from Bogoliubov's dispersion relation, plus energy and momentum conservation, show that, in order to create an excitation, the impurity must move with an initial velocity

 

LinearAlgebra[Norm](`#mover(mi("v"),mo("&rarr;"))`) >= v[c] and v[c] = sqrt(G*n/m)

 

  

When LinearAlgebra[Norm](`#mover(mi("v"),mo("&rarr;"))`) < v[c] , no excitation can be created and the impurity moves through the medium without dissipation, as if the viscosity is 0, characterizing a superfluid. This is the Landau criterion for superfluidity.

 

b) Show that when the atom-atom interaction constant G >= 0 (repulsive interactions), this value v[c] is equal to the group velocity of the excitation (speed of sound in a condensate).

Solution

   

 

References

NULL

[1] Suppression and enhancement of impurity scattering in a Bose-Einstein condensate

[2] Superfluidity versus Bose-Einstein condensation
[3] Bose–Einstein condensate (wiki)

[4] Dispersion relations (wiki)

 


Download QuantumMechanics3.mw   QuantumMechanics3.pdf

Edgardo S. Cheb-Terrab
Physics, Maplesoft

As a reminder, we regularly host live webinars on a variety of topics for our customers, and we wanted to make this information available to the MaplePrimes community as well.

This featured webinar for this month will outline the Finance Package in Maple 18 including capabilities like the mathematical, statistical, and connectivity tools required to analyse data, calculate forecasts, estimate risks, prototype and develop quantitative algorithms, and leverage parallel programming techniques.

Other topics include:

• Data feed connectivity and system integration

• Price equity and interest rate derivatives

• Populate reporting tools, deliver documents and share worksheets

• Optimize portfolios of financial instruments

• High-Performance Computing (HPC)

To join us for the live presentation, please click here to register.

I'll start with a quick positive.  One of the great advantages of upgraded software is the wealth of new features that we all get to play around with.  .. and then I will counter that with a great disadvantage, and that is, we all just about get familiar and comfortable with all the new features then BAM! a new version is released.  Of course we're then mesmorized once again by all the new bells and whistles and maybe even a couple of great celebrations occur with nice small updates throughout the year.  The other downside is that even though a large number of bugs may have been fixed a number of new ones are broght in with those new features. 

A side effect of a fast release is there are fewer and fewer applications associated with a release, and that is apparent in the application center.  Although mobius apps and the maple cloud may have also had some impact on that as well.

Now this is pale in comparison to book writers who scramble to keep their books current with new software.  I will quote a section from the introduction in the book Essential Maple 7 which highlights the problems the author had way back then .. I can't imagine how they feel now but here's the passage ...

"Indeed, one reason that there was so much time between the first and second
editions of this book is precisely that Maple has been evolving so rapidly in the
last few years, too rapidly for me to revise this book (much less complete my
others) while coping with my other duties."

That just hits the nail on the head, if you think Maple was evolving fast back then, the furious rate that upgrades are released now I would think authors have an almost impossible task to keep up. 

There are many that would agree with the author, that Maple is advancing so rapidly that we barely have time to gather our thoughts.  Maybe a solution is that we should slow down and create a much more polished piece of software, but again the caveat to that is our competition might just jump out in front.  However the norm today is that each new year represents a new release of software and we all celebrate when that happens.  If life seemed rushed back when Maple 7 was released I can't imagine what it'll be like 10 years from now when Maple 28 rolls around. 

Addition, subtraction, scalar product, vector, projections and graphs with physics packages and plots. With this you can begin to start the physics course for engineering.

Operaciones_con_Vect.mw   (in spanish)

 

Lenin Araujo Castillo

Physics Pure

Computer Science

Greetings to all.

I would like to share a brief observation concerning my experiences with the Euler-Maclaurin summation routine in Maple 17 (X86 64 LINUX). The following Math StackExchange Link shows how to compute a certain Euler-MacLaurin type asymptotic expansion using highly unorthodox divergent series summation techniques. The result that was obtained matches the output from eulermac which is definitely good to know. What follows is the output from said routine.

> eulermac(1/(1+k/n),k=0..n,18);
     1       929569        3202291        691                O(1)
O(- ---) - ----------- + ----------- - --------- + 1/1048576 ----
     19             15            17          11              19
    n      2097152 n     1048576 n     32768 n               n

                                           n
                                          /
        174611      5461        31       |      1           17        1
     - -------- + --------- + ------- +  |   ------- dk - ------- + ------
             19          13         9    |   1 + k/n            7        5
       6600 n     65536 n     4096 n    /                 4096 n    256 n
                                          0

         1       1
     - ------ + ---- + 3/4
            3   16 n
       128 n

While I realize that this is good enough for most purposes I have two minor issues.

  • One could certainly evaluate the integral without leaving it to the user to force evaluation with the AllSolutions option. One can and should make use of what is known about n and k. In particular one can check whether there are singularities on the integration path because we know the range of k/n.
  • Why are there two order terms for the order of the remainder term? There should be at most one and a coefficient times an O(1) term makes little sense as the coefficient would be absorbed.

You might want to fix these so that the output looks a bit more professional which does enter into play when potential future users decide on what CAS to commit to. Other than that it is a very useful routine even for certain harmonic sum computations where one can use Euler-Maclaurin to verify results.

Best regards,

Marko Riedel

 

It seems that

 

Limit(N+(sum((-1)^n*Sum(1/n^x, x = 1 .. N), n = 1 .. infinity)), N = infinity)=log(2)

 evalf(300+sum((-1)^n*(Sum(1/n^x, x = 1 .. 300)), n = 1 .. infinity), 30)

gives

0.693147180559945309417232121.

 sum(1/n^x, x = 1 .. infinity)

gives

1/(n-1).

In Maple 18, the Database package has been updated to include support for SQlite databases as well as a new option for plots to change the background images on plots.  To showcase both of these features, our engineering team put together an example that optimizes the flight path of a pan-US delivery drone.

This application extracts the latitude and longitude of those zip codes from an SQLlite database (the application includes the database, which cross-references US zip codes against their latitude, longitude, city and state). The application then performs a traveling salesman optimization and plots the shortest path on a map of the US.

To download the application click here: PanUSDeliveryDro.zip

This is a 5-days mini-course I gave in Brazil last week, at the CBPF (Brazilian Center for Physics Research). The material will still receive polishment and improvements, towards evolving into a sort of manual, but it is also interesting to see it exactly as it was presented to people during the course. This material uses the update of Physics available at the Maplesoft Physics R&D webpage.

Mini-Course: Computer Algebra for Physicists

 

Edgardo S. Cheb-Terrab

Maplesoft

 

 

This course is organized as a guided experience, 2 hours per day during five days, on learning the basics of the Maple language, and on using it to formulate algebraic computations we do in physics with paper and pencil. It is oriented to people not familiar with computer algebra (sections 1-5), as well as to people who are familiar but want to learn more about how to use it in Physics.

 

Motivation

 

 

Among other things, with computer algebra:

 

• 

You can concentrate more on the ideas (the model and its formulation) instead of on the algebraic manipulations

• 

You can extend your results with ease

• 

You can explore the mathematics surrounding your problem

• 

You can share your results in a reproducible way - and with that exchange about a problem in more productive ways

• 

After you learn the basics, the speed at which algebraic results are obtained with the computer compensates with dramatic advantage the extra time invested to formulate the problem in the computer.

 

All this doesn't mean that we need computer algebra, at all, but does mean computer algebra can enrich our working experience in significant ways.

What is computer algebra - how do you learn to use it?

   

What is this mini-course about?

   

What can you expect from this mini-course?

   

 

Explore. Having success doesn't matter, using your curiosity as a compass does - things can be done in so many different ways. Have full permission to fail. Share your insights. All questions are valid even if to the side. Computer algebra can transform the algebraic computation part of physics into interesting discoveries and fun.

1. Arithmetic operations and elementary functions

   

2. Algebraic Expressions, Equations and Functions

   

3. Limits, Derivatives, Sums, Products, Integrals, Differential Equations

   

4. Algebraic manipulation: simplify, factor, expand, combine, collect and convert

   

5. Matrices (Linear Algebra)

   

6. Vector Analysis

   

7. Tensors and Special Relativity

   

8. Quantum Mechanics

   

9. General Relativity

   

10. Field Theory

   

BrasilComputacaoAlgebrica.mw.zip

BrasilComputacaoAlgebrica.pdf 

Edgardo S. Cheb-Terrab
Physics, Maplesoft

We regularly host live webinars on a variety of topics for our customers, and we wanted to make this information available to the MaplePrimes community as well. We will be posting information about new webinars we think will be of interest approximately once per month.

Partnering with the MAA to Revolutionize Placement Testing

In this webinar, we will demonstrate how the Maple T.A. MAA Placement Test Suite can be used to ease the problem of placement testing and how it can benefit your campus in general.

Other topics include:

• How placement testing contributes to student success

• How the MAA placement tests are created, and rigorously validated

• How valid and reliable the MAA placement tests are for entry level mathematics courses

• How you can use the Maple T.A. Placement Test Suite for easy administration, flexible delivery, and fast results

To join us for the live presentation, please click here to register.

At the user stored question list for every user stored at maplesoft, all posted dates are correct however at mapleprimes the dates start at April 2010 ???

Also, unfortunately the question list at maplesoft seems to all end Oct 2013.  I'm not really sure what happened there.  But when I'm trying to search for something I qustioned or posted after Oct 2013 from that list is not going to happen.

That list was the best thing!  All of your questions and posts ever created are in chronological order making it quite easy to locate a question you were looking for.

I just wanted to remind everyone that this quarter's Möbius App Challenge closes on March 31st.  The next prize to be awarded is an Xbox One Prize Pack.  Video games are supposed to be good for the brain, after all, so really, you owe it to yourself to enter.

To enter the contest, all you need to do is:

1) Create an interactive App in Maple

2) While in Maple, log-in to the MapleCloud through the MapleCloud palette.

3) Click on the Send Document to the Cloud button

4) Set the group to "Mobius@admin", then hit send.

The group is moderated, so it won't appear instantly, but once approved it will appear on the Möbius Project server, where people can interact with it through a web browser, in Maple, or download it for use with the free Maple Player.

Here are the full contest details and more information on creating and submitting Apps.

Good luck!

Kim

In this post we present the solution with Maple to the logical problem of "Gardens Puzzle"

http://www.mathsisfun.com/puzzles/gardens-solution.html

The Puzzle:

Five friends have their gardens next to one another, where they grow three kinds of crops: fruits (apple, pear, nut, cherry), vegetables (carrot, parsley, gourd, onion) and flowers (aster, rose, tulip, lily).

1. They grow 12 different varieties.
2. Everybody grows exactly 4 different varieties
3. Each variety is at least in one garden.
4. Only one variety is in 4 gardens.
5. Only in one garden are all 3 kinds of crops.
6. Only in one garden are all 4 varieties of one kind of crops.
7. Pear is only in the two border gardens.
8. Paul's garden is in the middle with no lily.
9. Aster grower doesn't grow vegetables.
10. Rose growers don't grow parsley.
11. Nuts grower has also gourd and parsley.
12. In the first garden are apples and cherries.
13. Only in two gardens are cherries.
14. Sam has onions and cherries.
15. Luke grows exactly two kinds of fruit.
16. Tulip is only in two gardens.
17. Apple is in a single garden.
18. Only in one garden next to Zick's is parsley.
19. Sam's garden is not on the border.
20. Hank grows neither vegetables nor asters.
21. Paul has exactly three kinds of vegetable.

Who has which garden and what is grown where?

 

About methods of solution. At first I just wanted to generate all variations and using conditions 1 .. 21 to find all solutions. But even if we use the condition that everybody grows exactly 4 different varieties then the total number variants equals  5!^2*binomial(12,4)^5=427945522455000000

So from the very beginning using some of the conditions 1 .. 21 we maximally reduce the number of possible variants. For example from the conditions 11, 18 and 6 implies that only in one garden are all 4 varieties of flowers. Next we pass through these variants and using conditions 1 .. 21 and finally come to a unique solution:

restart;

Fruits:={apple, pear, nut, cherry}:

Vegetables:={carrot, parsley, gourd, onion}:

Flowers:={aster, rose, tulip, lily}:

 

Set1:=Flowers:

Garden1:={Set1}:

Set2:=Fruits union Vegetables union Flowers minus {nut,gourd,parsley} minus {apple,cherry,rose}:

Garden2:={seq({nut,gourd,parsley} union {Set2[i]}, i=1..nops(Set2))}:

Set3:=Vegetables union Flowers minus {parsley}:

Garden3:={seq({apple,cherry,pear} union {Set3[i]}, i=1..nops(Set3))}:

Set4:=combinat[choose](Fruits union Vegetables union Flowers minus {onion,cherry} minus {apple,parsley,pear,nut}, 2):

Garden4:={seq({onion,cherry} union Set4[i], i=1..nops(Set4))}:

Set5:=Fruits union Vegetables union Flowers minus {apple, cherry,nut,parsley}:

Garden5:=combinat[choose](Set5, 4):

 

S:=[]:

for s1 in Garden1 do

for s2 in Garden2 do

for s3 in Garden3 do

for s4 in Garden4 do

for s5 in Garden5 do

s:=[s1,s2,s3,s4,s5]: s_4:=combinat[choose](s,4): m:=0: n:=0: k:=0: p:=0: q:=0:

for i in s do

if `intersect`(i,Fruits)<>{} and `intersect`(i,Vegetables)<>{} and `intersect`(i,Flowers)<>{} then m:=m+1: fi:

if pear in i then n:=n+1: fi:

if tulip in i then k:=k+1: fi:

if aster in i and `intersect`(i,Vegetables)<>{} then p:=p+1: fi:

if i=Fruits or i=Vegetables or i=Flowers then q:=q+1: fi:

od:

if nops(`union`(op(s)))=12 and nops(`union`(seq(`intersect`(op(s_4[j])), j=1..nops(s_4))))=1 and m=1 and n=2 and k=2 and p=0 and q=1 then S:=[op(S),[s1,s2,s3,s4,s5]]: fi:

od: od: od: od: od:

 

L1:=[seq([[3,Paul],[2,Sam],seq([combinat[permute]([1,4,5])[i,j],[Luke,Zick,Hank][j]],j=1..3)],i=1..6)]:

L2:=[seq([[3,Paul],[4,Sam],seq([combinat[permute]([1,2,5])[i,j],[Luke,Zick,Hank][j]],j=1..3)],i=1..6)]:

L0:=[op(L1),op(L2)]:

L:=[seq(op(combinat[permute](L0[i])),i=1..nops(L0))]:

Sol:=[]:

for l in L do

for s in S do

sol:=[seq([op(l[i]),s[i]], i=1..5)]:

gad1:=op(select(has,sol,parsley)): gad2:=op(select(has,sol,Zick)):

if abs(gad1[1]-gad2[1])=1 and convert([seq(((pear in sol[i][3] implies (sol[i][1]=1 or sol[i][1]=5)) and (sol[i][2]=Paul implies (not lily in sol[i][3])) and (sol[i][1]=1 implies (apple in sol[i][3] and cherry in sol[i][3])) and (sol[i][2]=Sam implies (onion in sol[i][3] and cherry in sol[i][3])) and (sol[i][2]=Luke implies nops(`intersect`(sol[i][3],Fruits))=2) and (sol[i][2]=Hank implies (`intersect`(sol[i][3],Vegetables)={} and not aster in sol[i][3])) and (sol[i][2]=Paul implies nops(`intersect`(sol[i][3],Vegetables))=3)), i=1..5)], `and`) then Sol:=[op(Sol), sol]: fi:

 

od: od:

for i in Sol do

Matrix(sort(i,(x,y)->x[1]<y[1]));

od;

 

 

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